He didn’t break Smith’s hand again, but Johnson hunted the South African skipper with a brutal bouncer that will give him nightmares.

Smith took his time before fronting up to Johnson in the second over, just a hint of panic in his preparation. The first bouncer struck him on the thigh, but the second caught him no man’s land and all he could do was ramp it over the slips to Shaun Marsh, who took a tumbling catch.

But that was nothing compared to the delivery that undid Faf du Plessis.

At 151km it was virtually unplayable. Not quite a bouncer but short of a length, du Plessis edged it behind to Michael Clarke at second slip.

Peter Siddle chipped in with the wicket of Hashim Amla, getting him leg before for 17 after asking for a review. But it was that man Johnson again who ripped through South Africa’s top-order, ending with figures of 4-51.

News_Rich_Media: Steve Smith claimed his fourth Test century with a fine knock of 100 on day two against South Africa, before being dismissed with his next ball.

Earlier, Shaun Marsh and Steve Smith put Australia in a commanding position, helping Australia reach their first innings total of 397.

But a late comeback, spearheaded by Proteas paceman Dale Steyn who took 4-78, restricted Australia.

Smith continued to impress after hitting a century, while Shaun Marsh reached his highest ever Test score of 148.

Both batsmen were dismissed before lunch, but not before putting Australia in total control.

It was Smith’s third ton in his last four Test matches and, crucially, they have all been scored in the first innings to halt an Australian batting collapse. Smith faced 211 balls for his hundred, but nicked a Ryan McLaren delivery behind to Alviro Petersen at second slip the next over. It was a frustrating way to go after a hard-fought knock and his wicket sparked a fight-back from the Proteas.

News_Rich_Media: Mitchell Johnson's dismissal of Graeme Smith on day two of Australia's Test against South Africa revived memories of his stunning performance to see off the captain in 2009.

Together Smith and Marsh put on 233 runs, the highest fifth wicket partnership at Centurion, to put the visitors in a dominant position.

Steyn and Vernon Philander started well, finding their line and length far more consistently than they did on the first day.

Marsh eventually fell to Philander when he edged one behind to Smith. His memorable innings is likely to cement his spot in Australia’s Test team for the series, be it at the expense of Shane Watson or Chris Rogers.

In a touching gesture, the Australian team wore black armbands in honour of Luke Batty, the 11-year-old from Tyabb Cricket Club who was tragically killed by his mentally ill father while at cricket practice on Wednesday.